Point-of-care measurements require portable and inexpensive devices, that allow physicians to conduct diagnostic tests in the surgery and that have the potential for home self-testing. These devices need to be reliable and inexpensive, while still providing sufficient sensitivity for clinically relevant analytes. Currently, a significant number of markers are available for diagnosing and analyzing the progress of diseases using immunoassays. Furthermore, key biomarkers, for example for cardiovascular disease (CVD), are increasingly used for risk monitoring for individuals and populations, in order to predict the likelihood of developing specific diseases.
It is therefore desirable to be able to screen for a number of relevant analytes simultaneously on one platform for efficient risk stratification and disease diagnosis. Fluoro-immunoassays, using fluorescently labelled biomarkers, are a common method for screening and measuring analytes. These techniques typically involve patterned arrays of biorecognition elements which are imaged using an optical readout system. There is an increasing requirement to detect low levels of analyte in small volumes which necessitates the use of high sensitivity readout systems. Signal enhancement strategies for optical biochips include plasmonic enhancement, high brightness nanoparticles and the use of high collection efficiency optics.
Despite these known solutions there is still a need for a system and methodology that will provide for efficient detection of target analytes.